NEET Physics Question - Modern Physics - Photoelectric Effects and deBroglie Equation

Assertion (A): In photoelectric effect, cathode or emitter plate is usually coated with barium oxide, barium sulphide or strontium oxide.

Reason (R): Coating prevents cathode from erosion.

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Both (A) & (R) are true but the (R) is not the correct explanation of the (A)

(A) is true but (R) is false

Both (A) and (R) are false

Solution:

Cathodes are coated with materials like barium oxide to lower their work function, enhancing photoemission efficiency. So (A) is true. Coatings can indeed prevent erosion, so (R) is also true. However, preventing erosion is not the primary reason for choosing these specific low work function materials, so (R) is not the correct explanation for (A).

Rankers Physics

Photoelectric Effect Cathode Coating

Solution:

Leave a Reply Cancel reply